I don't see what was so objectionable about this; more Coloradans opposed a tobacco tax to promote health than voted for this measure.
It purported to apply itself to an election being held on the same date. In effect, the meaning of a vote for Kerry would have a different meaning if the proposition passed, than if the proposition failed. The manner by which electors were chosen, would be changed at the same time that the electors were chosen.
It also included provisions for changing the timing of how a constitutional amendment would come into force so that the electors could be appointed on time to vote. So the measure in effect said, if this proposition passes, the method of determining that this initiative proposition has passed will be changed for this proposition.
And then it included a serverabilty clause, that meant that in the case the proposition caused a train wreck magnitudes worse than Florida 2000, that the supporters would shrug their shoulders and say, "oh yeah, it won't apply until 2008.
The backers were Democrats from California and Ohio, who were deliberately trying to steal a few electoral votes in what was anticipated as being a close electoral vote (flip Ohio and Wisconsin, for example). This also explains the support in Aspen and Telluride.
Under most circumstances, a state with a relatively small even number of electoral votes would end up with a 50:50 split. In a two-way contest with 8 electoral votes, the winner would need a 56.25:43.75% win (12.5% victory to get a 5:3 split). But because of the peculiar way of doing the "proportional" allocation, in Colorado in 2000 there would have been 5:3 split for Bush.